Finding the Fourth Proportional to 1,530.39, 2,111.87 and 831.77

Step by Step Solution

1. Step 1: Write the proportion equation
   1,530.39 : 2,111.87 = 831.77 : x
2. Step 2: Convert to fraction form
   1,530.39/2,111.87 = 831.77/x
3. Step 3: Cross multiply
   1,530.39x = 2,111.87 × 831.77
4. Step 4: Simplify right side
   1,530.39x = 1,756,589.55
5. Step 5: Solve for x
   x = 1,756,589.55/1,530.39
6. Step 6: Final answer
   x = 1,147.80